In the industry, printed circuit boards (PCB's) when manufactured are assembled by affixing a plurality of PCB's to a panel. By affixing a plurality of PCB's to a panel, substantial savings of time, material and money have been obtained as handling a plurality of PCB's simplifies and speeds up the automated processing of the PCB's. As the commercial demands of PCB's in the electronics industry increases, the plurality of PCB's assembled on a single panel require more efficient handling by the processing equipment.
An important consideration in the processing of the PCB's is the removal of the individual PCB from the panel for further processing or installation into the finished product, such as a computer or other electronic equipment. Efficiently removing the PCB's from the panel allows more panels to be processed, resulting in economic gain.
Removing the PCB's from the panel is referred to as “depaneling” or “liberating” the PCB's from the panel. Methods presently used in the industry to depanel each individual PCB from the interconnected PCB's in the panel have typically included shearing, routing, break-away methods of routed tabs, scoring, perforation, and various punch and die techniques.
Routing employs cutting rout slots in the panel around individual PCB's to define the perimeter of the individual PCB. As such, the routing leaves support tabs around the perimeter for holding the individual boards in place. Such tabs are then cut, broken, or routed to remove each board.
Scoring utilizes grooving lines along portions of individual board perimeters. Such score lines are then used as weak areas to separate the board by breaking the PCB from the panel along the score lines. In addition, various perforations have been used to define the perimeters of the individual boards. Breaking along the lines of perforation is then used to depanel the individual boards. Other methods of depaneling include punch and die techniques wherein a custom made die is used to punch each individual board out of the panel.
These methods of depaneling contain deficiencies, however. The present scorers reduce the rigidity of the panel. Accordingly, the panels are prone to sagging during further processing after one of the PCB's is separated. As a result of the sagging, the subsequent PCB's are not as accurately processed. Perforation and scoring yield very poor quality edges. Accordingly, the edges cannot be held to close tolerances. Additionally, the punch and die method requires expensive tooling as the punch and die is custom made with respect to the panel. Thus, panels having different configurations require different punches and dies. Additionally, the tooling needs to be replaced with each new panel, requiring further downtime of the punch and die.
Thus, a need exists for a high volume and high speed depaneling of PCB's from panels containing a plurality of PCB's. A need also exists for a router which enables damage free depaneling of the PCB from the panel. Further, a need exists for a router that depanels the PCB from a location above the PCB. Additionally, a need exists for a router that can be programmed to read a panel configuration and depanel the PCB without changing any tooling.
Devices are known in the industry that accept a panel of PC boards and depanel the individual PC boards. U.S. Pat. No. 5,894,648, issued to Hill, discloses a depaneling apparatus that removes the individual PCB from the panel and automatically positions the separated PCB to a registration area. The depaneler then automatically moves the PCB from the registration area to a subsequent processing station. In this depaneler, the PCB is depaneld by a router that cuts the PCB from underneath the panel.
This depaneler contains deficiencies, however. Design constraints of an assembly line may not allow the routing mechanism to be underneath the panel. Further, locating the router under the area where the panel is to be processed limits access to the router. Thus, during maintenance or breakdowns, more time is needed to access the router, resulting in less operation time and increased maintenance costs. Further, in some assemblies, it may not be practical to automatically move the separated PCB to a further processing station. Further, the depaneler requires a loading track to position the panel for routing, which may not be practical with regard to the allowable workspace.
Another approach is disclosed in U.S. Pat. No. 4,742,615 issued to Lopez, which recites a routing method and apparatus. This device, however, positions the router underneath the panel and routs from below, which may be impractical due to workspace limitations. Further, this device can only rout one predetermined set of panels as opposed to adapting to rout panels with different configurations.
Another approach is disclosed in U.S. Pat. No. 5,067,229 issued to Nakamura, which recites a cutting device for electronic components. This cutting device also cuts from underneath the panel. Further, the device requires an identification pattern consisting of eight sections of coated and non-coated sections of the panel in order for the device to sense which type of panel is to be processed, adding to the complexity and cost of the cutting device.